Many bars and restaurants currently offer draft beer and other beverages to their customers. A number of customers prefer draft beer instead of bottled beer; however, it is difficult for bar owners and managers to make sure that the amount of draft beer dispensed is equal to the amount actually sold. Large amounts of draft beer are wasted or otherwise unaccounted for through sloppy pouring by bartenders, premature opening of taps before a container is in position to be filled, and giving away of draft beer by bar staff.
Several types of devices have been developed to monitor the amount of beverage flowing through a dispensing unit. For example, U.S. Pat. No. 4,979,641 to Turner discloses a computerized beverage dispensing system having a valve and a computerized controller connected to the tap. The beverage flows from the tap into the monitoring device wherein the flow is either restricted or permitted by the valve. The controller is programmed by the operator to open the valve for a certain length of time when the tap is opened to dispense a predetermined amount of beverage.
Similarly, U.S. Pat. No. 3,965,337 to Young describes a monitor in which the amount of beer dispensed is indicated in terms of the sales price. Beverage dispensing is controlled by a pair of pulsers which operate at different rates associated with the dispensing of a glass or a pitcher of beer. The glass-rate pulser is actuated when the dispensing tap is initially opened. If the tap remains open for a period of time greater than that required to fill a glass, the pitcher-rate pulser is automatically actuated.
These types of draft beer monitors require the operator to preprogram into the monitor the amount of beer to be dispensed. Devices of this type often require fluid flow through the device for measurement of flow velocity or pressure. This requirement makes the monitoring unit relatively difficult to install onto the dispensing unit. Additionally, monitors of this type may interfere with the flow of beer through the tap.